Security of Radioactive Sources the Evolving New International Dimensions
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SECURITY OF RADIOACTIVE SOURCES THE EVOLVING NEW INTERNATIONAL DIMENSIONS BY ABEL J. GONZALEZ ecurity of radioactive also is known as a radiological moon-suited cleaning crews with sources has become an dispersal device, or RDD. Geiger counters in a big city Sissue of serious public Such a weapon would not downtown is bound to cause concern after the devastating create a nuclear explosion panic.” terrorist attacks of 11 Septem- with its dreaded mushroom The “dirty bomb”scenario is ber 2001. Yet it is worth cloud producing calcinating certainly not unique in the asking how serious the the heat, devastating shock waves menu of nuclear terror. problem actually is, given the and vast amounts of Nuclear installations with large fact that hundreds of radioactive fallout. radioactivity inventories, such dangerous chemicals and Although there have been as nuclear power plants and biological agents pose perhaps unfounded suggestions that a radioactive waste depositories, greater terrorist threats that dirty bomb explosion would can be attacked and their need to be urgently reduced. kill thousands and render radioactive materials dispersed. Radioactive sources do not entire cities uninhabitable, In the worst nightmare contain the type of nuclear these scenarios of devastation scenario, a nuclear weapon can materials that would allow are highly exaggerated. If such fall into terrorist hands, and someone to build a nuclear an attack actually occurred, the detonation of a nuclear 39 bomb and trigger a major the device would probably device with even a small catastrophe. Though scatter radioactive material nuclear yield in a major radioactive sources can be over a small area, restricting metropolitan area is sure to potentially dangerous for contamination to possibly a have devastating effects. anyone coming into close few city blocks. Casualties The odds of a radiological contact with them, they are affected by the radiation dispersal device falling into safely used in everyday life for would be limited, and the malevolent hands have medical care and treatment, perpetrators likely would be triggered particular public among other applications in harmed by direct radiation anxiety, perhaps because the fields of industry, agriculture, exposure from manipulating likelihood is perceived to be and science. the source. higher. Fears have been largely However, there is increasing However, even if an RDD augmented by the aftermath apprehension that radioactive would not injure many people, trauma caused by the New sources could be turned into a it could certainly cause much York and Washington attacks. terrorist tool — what the terror and psychological distress. Not surprisingly, security of media call a “dirty bomb”. The media recently stated that radioactive sources has been This term is used to describe a “in the wrong hands, even a placed high on the radioactive source shrouded relatively small amount of international agenda. by a conventional explosive radioactive material can cause The need for securing (similar to TNT), obviously the kind of low-grade terror seen radioactive sources is not new. built with malevolent intent. in the spate of anthrax-laced Security has always been If detonated in a public mail sent to US government and required for preventing domain, this mélange could media offices”. Moreover, they cause widespread reported that “terror, indeed, Mr. González is Director of the dissemination of radioactive appears to be a dirty bomb’s IAEA Division of Radiation and particles and for this reason it greatest attraction: the image of Waste Safety,. IAEA BULLETIN, 43/4/2001 CLARIFYING ISSUES & TERMS Safety & Security. Public apprehension generated by the new security dimension runs parallel with (and is perhaps enhanced by) confusion over technical terms and issues, often exacerbated by translation. The IAEA has long recognized this problem and comprehensively reported on it.* Safety and security — “sûreté and sécurité” — are two distinct terms in English and French; in many other major languages, a common word is used for these two concepts. Not surprisingly, therefore, many people wonder what the distinction is between safety and security. If they reached for their dictionaries, they would perhaps be none the wiser, because one of the definition of security is safety and vice versa. In the context of radiation sources, both words are used to denote a combination of administrative, technical and managerial features for two different purposes that can occasionally coincide but may also clash. radioactive elements such as cobalt-60 and caesium- ■ Safety of radiation sources is used to cover features 137, which are widely used in radiological medicine that diminish the likelihood of accidents with a source, and industry. A radioactive source never ceases to as a result of which people may be injured, as well as to emit radiation but the radiation intensity decays cover those that may mitigate the consequences of over time depending on the type of radioactive such mishaps. elements in the source. The term half-life is used to ■ Security of radiation sources refers to the features that indicate the period in which the radioactivity 40 prevent any unauthorized possession of the source and, decreases by half due to radioactive decay. For as a result, any non-permitted action with it. Security instance, as caesium-137 has a half-life of around 30 is achieved by ensuring that control of the source is years, a radiation source of this radioactive element not relinquished and improperly acquired. diminishes its intensity by half every 30 years. Radiation & Radioactive Sources. Frequently, the Security of Radioactive Sources: Clarifying Aims. terms radiation and radioactive are interchangeably Security of radioactive sources aims to ensure that misused to qualify a source. This misrepresentation control of radioactive materials is not relinquished has also been a cause of confusion. Some devices can be and improperly acquired, therefore preventing such sources of radiation without necessarily being materials from going astray and causing harm to “radioactive”. people and the environment or from being diverted ■ Typical non-radioactive radiation sources are various for malevolent acts such as terrorism. While safety is types of electrical generators of radiation, such as X-ray of relevance to all types of radiation sources, either machines and particle accelerators, which emit non-radioactive or radioactive, security is usually radiation while in operation but whose emitting limited to radioactive sources alone. properties cease as soon as the electricity supply is cut. Sometimes safety and security oppose each other: ■ Conversely, radioactive radiation sources (or for instance, the clear marking of radioactive sources radioactive sources for short) contain radioactive is imposed on safety grounds, but it makes materials, namely substances formed by radioactive radioactive sources more vulnerable to security elements emitting radiation themselves (the so-called breaches. The dichotomy has become evident in radioactive elements). Typical examples of discussions of the controversial issue of transporting radioactive sources are the sealed capsules containing radioactive sources by sea: while many coastal States request that comprehensive information on sources *See Vol. 41, No. 3, which covers issues of radiation being transported near their shores must be provided safety and security, accessible on the IAEA’s by transporter States because of safety, the latter WorldAtom site at http://www.iaea.org/worldatom/ prefer to keep information restricted for reasons of Periodicals/Bulletin. security. IAEA BULLETIN, 43/4/2001 radioactive materials going nuclear power production. radiation source in contact with astray, and, as a result, causing Nuclear materials, devices and tissue (a technique usually harm to people. Security of facilities are both scarcer and called brachytherapy, which radioactive sources has always better secured than radioactive comprises the interstitial been an important component sources. intracavitary, intraluminal, and of the IAEA radiation safety Abundance of Radioactive superficial applications of programme. In mid-1999, the Sources. Radioactive sources sources). Teletherapy can also be IAEA Bulletin (Vol. 41, No.3) are extensively and commonly performed with “accelerators”, a covered it extensively in an used in a wide range of non-radioactive radiation source edition, focusing on the IAEA medical, industrial, agricultural which, as the X-ray machines, response to key problems. and research applications. They do not present an evident Today, in the face of the vary widely in physical size and security threat. new challenges presented by properties, their amount of Many medical sources are the recent terrorist attacks, a radioactivity, and ease of mainly made from the new dimension of security access. The radioactivity of a radioactive element termed emerges: deterring the source is measured in units cobalt-60, which is a metal and diversion of radioactive termed becquerel (abbreviated has a half-life of around 5 years. materials from legal to illegal Bq). Years ago the unit termed Less frequently, the radioactive and criminal uses – such as curie (Ci) was widely employed element caesium-137, with a terrorist violence. The IAEA is and is still used. One becquerel half-life of around 30 years, is adjusting its response to this is a tiny amount of radio- employed. Many caesium new and remarkable reality. In activity.